ALBANY – Moving to exploit an increasingly lucrative insider business, two of New York’s best-known Republicans have formed a new lobbying firm, The Post has learned.

Former Rep. Bill Paxon, husband of for- mer Rep. Susan Molinari of Staten Island, and Clarence “Rapp” Rappleyea, the ex-head of the state Power Authority and the longtime minority leader of the Assembly, will set up shop within days as the HB-AG Public Affairs Group, sources said.

The new firm, which will have strong ties to Gov. Pataki’s administration and the GOP-controlled Senate, may find itself in competition with another new lobbying outfit, Powers, Crane & Co., which was set up earlier this year by William Powers, who recently resigned as chairman of the state GOP.

“This could make for some interesting competition among lobbyists who claim to have Pataki’s ear,” said a prominent Albany lobbyist.

The Paxon-Rappleyea combination is a joint venture of two politically connected law firms, the New York-based Harris Beach – a sponsor of Pataki’s ongoing fund-raising swing through California – and Washington-based Akin, Gump, Strauss, Hauer and Feld, which counts Democratic heavyweight Vernon Jordan among its partners.

Formation of the new firm comes just weeks after the state Lobbying Commission reported that a few dozen lobbying firms earned a record $60-plus million last year seeking to influence Pataki and both houses of the Legislature.